sudo appstreamcli refresh-index --verbose --force
** (appstreamcli:6582): DEBUG: Refreshing AppStream cache
** (appstreamcli:6582): DEBUG: Reading: /usr/share/app-info/xmls/org.freedesktop.fwupd.xml
** (appstreamcli:6582): DEBUG: WARNING: Invalid component: [Component::com.steelseries.rival-legacy.firmware]> name: (null) | package: ? | summary: (null)
** (appstreamcli:6582): DEBUG: Reading: /var/lib/app-info/yaml/us.archive.ubuntu.com_ubuntu_dists_xenial_main_dep11_Components-amd64.yml.gz
** (appstreamcli:6582): DEBUG: Reading: /var/lib/app-info/yaml/us.archive.ubuntu.com_ubuntu_dists_xenial_restricted_dep11_Components-amd64.yml.gz
** (appstreamcli:6582): DEBUG: Reading: /var/lib/app-info/yaml/us.archive.ubuntu.com_ubuntu_dists_xenial_universe_dep11_Components-amd64.yml.gz
** (appstreamcli:6582): DEBUG: Reading: /var/lib/app-info/yaml/us.archive.ubuntu.com_ubuntu_dists_xenial_multiverse_dep11_Components-amd64.yml.gz
** (appstreamcli:6582): DEBUG: Reading: /var/cache/app-info/xmls/fwupd.xml
** (appstreamcli:6582): DEBUG: WARNING: Invalid component: [Component::com.dell.uefi124c207d.firmware]> name: XPS 15 9550/Precision 5510 System Update | package: ? | summary: Firmware for the Dell XPS 15 9550/Precision 5510
** (appstreamcli:6582): DEBUG: Detected colliding ids: plan.desktop was already added with the same priority.
** (appstreamcli:6582): DEBUG: Detected colliding ids: flcheckers.desktop was already added with the same priority.
** (appstreamcli:6582): DEBUG: Detected colliding ids: flblocks.desktop was already added with the same priority.
** (appstreamcli:6582): DEBUG: Detected colliding ids: flsudoku.desktop was already added with the same priority.
** (appstreamcli:6582): DEBUG: zathura-pdf-poppler.desktop extends zathura.desktop, but zathura.desktop was not found.
** (appstreamcli:6582): DEBUG: Removing old rebuild-dir from previous database rebuild.
AppStream cache update completed, but some metadata was ignored due to errors.